neutron: also drop -api job from master gate
neutron: also drop -api job from master gate

This is a follow-up to Ie9516b203ca2efee41931972357900afd54ec71a that
missed that the -api job was also in gate queue.

Change-Id: I0192478f8d3caaa1734e0ba52d29ff2c439960c1

openstack-infra/project-config,openstack-infra/project-config